Percutaneous prosthetic by-pass graft and method of use

ABSTRACT

A generally tubular prosthetic device is provided which includes a first stent having a central axis and a flow passage defined therethrough and being sized for insertion into a target lumen. A first, proximal member extends from a sidewall of proximal stent and is in fluid communication with the flow passage. A second, distal stent is provided having central axis and a flow passage defined therethrough and being sized for insertion into the target lumen. A second, distal member extends from a sidewall of the distal stent and is in fluid communication with the flow passage of the distal stent. The prosthetic device also includes a generally tubular central member that interconnects and fluidly couples the first and second stents via the proximal and distal members. A method of employing the device is also disclosed.

BACKGROUND OF THE INVENTION

This invention relates to a prosthetic device, and more particularly, toa prosthetic arterial bypass, venous bypass or arterial-venous graft.

When an artery or vein becomes occluded, a surgical procedure istypically performed by a vascular surgeon to restore proper blood flow.The known procedure includes a formal surgical incision and exposure ofthe blocked artery or vein. A prosthetic bypass member or a natural veinis then sutured to the blocked vessel both upstream and downstream ofthe occlusion so as to divert the flow of blood around the blockage.

A similar surgical procedure is required to place a graft between anartery and a vein, which is clinically used in dialysis patients. Suchformal surgical procedures require the use of an operating room and, asa result, are costly.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a non-surgicalprosthetic device and method for either bypassing an occlusion in alumen or for connecting two lumens, which eliminates the need for aformal surgical procedure.

In accordance with the principles of the present invention, thisobjective is obtained by providing a generally tubular prosthetic devicewhich includes first and second terminal stents. As used herein, theterm "prosthetic device" includes a device having natural or syntheticmaterials, or a combination thereof. The first stent, also referred toherein as the proximal stent, has a central axis and a flow passagedefined therethrough and is sized for insertion into a first portion ofa first target lumen. A first, proximal member extends from a sidewallof the proximal stent and is in fluid communication with the flowpassage. The proximal member is preferably inclined with respect to thecentral axis of the proximal stent.

The second terminal stent, also referred to herein as the distal stent,has a central axis and a flow passage defined therethrough and is sizedfor insertion into a second portion of the first target lumen or asecond target lumen. A second, distal member extends from a sidewall ofthe distal stent and is in fluid communication with the flow passage ofthe distal stent. The distal member is preferably inclined with respectto the central axis of the distal stent.

The prosthetic device also includes a generally tubular central memberthat interconnects and fluidly couples the first and second terminalstents via the proximal and distal members.

In accordance with another aspect of the present invention, a method ofinstalling a device within an occluded lumen so as to bypass theocclusion, or as a graft between two lumens, is provided.

The method includes the steps of making a puncture through a firstportion of a first lumen at one stent entry site; inserting a distalstent of the prosthetic device in a collapsed state through the punctureinto the first lumen; permitting the distal stent to expand so as toengage the interior wall of the first lumen; permitting a portion of thedistal stent to extend through the puncture; making a puncture through asecond portion of the first lumen or in a second lumen at another stententry site; inserting a proximal stent of the prosthetic device in acollapsed state through the puncture into the second portion of thefirst lumen or into the second lumen; permitting the proximal stent toexpand so as to engage the interior wall of the first or second lumen;permitting a portion of the proximal stent to extend through thepuncture; and disposing a central member in the skin and fascia betweenthe entry sites so as to fluidly couple the proximal and distal stentswithin subcutaneous tissue and fascia so that fluid may flow through theproximal stent, through the central member and through the distal stentso as to either bypass an occlusion or graft two lumens.

Other objects, features and characteristics of the present invention, aswell as methods of operation and functions of related elements of thestructure, and the combination of the parts and economics ofmanufacture, will become more apparent upon consideration of thedetailed description and appended claims with reference to theaccompanying drawings, all of which form a part of the specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a prosthetic device provided inaccordance with the principles of the present invention, shown installedin an occluded lumen;

FIG. 2 is a schematic illustration of a delivery device shown deliveringone end of the prosthetic device into the lumen; and

FIG. 3 is a schematic illustration of another embodiment of theprosthetic device showing one end thereof installed in a lumen.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EXEMPLARY EMBODIMENT

A device, generally indicated at 10, is shown for bypassing an occludedlumen or for coupling two lumens. Although the device may be employed aseither a bypass device or as a graft, the device 10 will be describedherein with reference to bypassing an occluded lumen.

The device 10 includes a proximal stent 12 for placement upstream of theocclusion and a distal stent 14 for placement downstream of theocclusion. A central member 16 fluidly couples the proximal and distalstents. As shown, the proximal and distal stents are disposed within thelumen, while the central member is disposed within the skin and fasciallayer, bypassing the occlusion.

The proximal stent 12 is generally tubular and has an inlet 17 and anoutlet 18. Furthermore, the proximal stent 12 is preferably acollapsible and expandable stent having a flow passage definedtherethrough. In the illustrated embodiment, the proximal stent is anexpandable metal mesh stent, however, it can be appreciated that anon-metallic stent may also be employed. Stents that are expandable upontemperature changes or stents that have "memory" properties may also beused. The proximal stent 12 includes a tubular proximal member 20coupled to and extending from a side thereof so as to be in fluidcommunication with the flow passage. The proximal member may be madeintegral with the proximal stent 12, if desired. The proximal member 20is preferably inclined with respect to the central axis A of theproximal stent 12. The proximal member 20 has an outlet 24 defined at anend thereof. Thus, the proximal stent 12 and the proximal member 20cooperate to define a generally "Y" shaped juncture, so as to minimizeturbulence of fluid flowing therethrough.

The device 10 also includes a generally tubular distal stent 14 which issimilar to the proximal stent 12. Thus, the distal stent 14 ispreferably a collapsible and expandable stent having a flow passagedefined therethrough. Like the proximal stent, the distal stent 14 ispreferably an expandable metal mesh stent. Again, it can be appreciatedthat a non-metallic stent may be employed. The distal stent 14 is openat both ends 30 and 32. The distal stent 14 includes a tubular distalmember 28 coupled to and extending from a side thereof so as to be influid communication with the flow passage of the distal stent. Thedistal member 28 may be made integral with the distal stent 14, ifdesired. The distal member 28 is preferably inclined with respect to thecentral axis B of the distal stent 14, toward the proximal member 20,the function of which will become apparent below. Thus, the distal stent14 and the distal member 28 cooperate to define a generally "Y" shapedjuncture, which reduces turbulence of fluid flowing therethrough. Thedistal member 28 is open at outlet 29. Outlet 29 of the distal member 28is directed generally toward outlet 24 of the proximal member 20, thefunction of which will became apparent below.

As stated above, the device 10 includes the generally tubular centralmember 16 disposed between and coupled to the distal and proximalmembers. The central member is preferably composed of PTFE(polytetrafluoroethylene) material or equivalent Food and DrugAdministration approved material. In the illustrated embodiment, ends 36and 38 are flared and disposed over the proximal and distal members 20and 28 respectively. When the device 10 is installed to bypass theblockage or to create a communication between an artery and a vein, theflared ends 36 and 38 extend into the lumen through the puncture so asto seal the puncture. As an alternative to providing the flared ends,ends of the central member may simply be attached to the proximal anddistal members and, preferably, a coating is provided on the proximaland distal members, extending onto the surface of the proximal anddistal stents to provide a seal.

It can be appreciated that ends 36 and 38 may be attached to theproximal and distal tubular members in any known manner as necessary ordesirable. In the illustrated embodiment, the ends 36 and 38 are hoodedover the tubular members. Thus, the ends 36 and 38 may then be sewn oradhered by adhesive to the tubular members to ensure a robustconnection. Alternatively, portions of the stents and tubular membersmay be covered with PTFE material or other coating, as indicated by thedashed lines in FIG. 1. The central member can then be sewn or adheredto the covered portions. Thus, in the illustrated embodiment, thetubular members are inclined in a direction toward one another, with thecentral member disposed therebetween, so as to facilitate fluid flowtherethrough. It may be appreciated, however, that the tubular membersmay be disposed substantially perpendicular to the central axes of thetubular members, if the grafting or bypass procedure so requires.

The central member 16 may be made available in a variety of lengths, oneof which may be selected for the procedure in question. Alternatively,the central member 16 may have an accordion-type configuration so thatthe length thereof may be adjusted.

FIG. 3 shows a portion of another embodiment of the prosthetic device 10of the invention. Only the proximal stent 112 of the prosthetic deviceis shown, however, it can be appreciated that the distal stent is ofsimilar construction. The central member 116 is identical to that shownin FIG. 1. The proximal stent 112 is substantially similar to theproximal stent 12 of FIG. 1. However, instead of permitting the tubularproximal stent 112 to extend beyond the proximal member 120, theproximal stent 112 terminates at a location where it is coupled to theproximal member 120, as shown if FIG. 3. In the illustrated embodiment,the proximal stent 112 includes an inlet 117 and an outlet 118. Thus,blood flowing in the lumen is directed through the proximal stent 112from inlet 117 through outlet 118 and also through the proximal member120, as shown by the arrows in FIG. 3. It can be appreciated, however,that the outlet 118 need not be provided in the stent 112 and bloodpassing through the lumen may pass directly through the mesh stent 112.Since the proximal stent 112 does not extend downstream of the proximalmember 120, retention braces 126 are preferably provided to enhance thestability of the device. One end of each retention brace 126 is coupledto the proximal stent 112 at opposing side surfaces thereof. The otherends of the retention braces 126 extend downstream of the proximalmember 120 and, when disposed in the lumen, contact the upper wall ofthe lumen to provide additional support to the device. Further, theproximal member 120 may include a lip 128 which engages the upper wallof the lumen to further enhance stability of the device 10 within thelumen. Thus, the "Y" configuration is maintained.

The installation of the device 10 will be appreciated with reference toFIGS. 1 and 2. A delivery device 37 for delivering the device 10 to thelumen is shown in FIG. 2. As shown, the device 37 includes an elongatedhollow member 39 which is large enough to house therein a stent and thecentral member in an adjacent relation. A guide wire 40 is disposedwithin a guide wire channel extending axially through the device 37 andis used for guiding the device 37 into the lumen 42. Alternatively, itcan be appreciated that the guide wire may be disposed through thecentral member 16, through member 20 or 28 and into the lumen so as toguide the device into the lumen. Stent 12 or 14 is disposed within thedevice 37 in a collapsed condition with the central member 16 coupledthereto. The guide wire 40 extends through the stent. A pusher member 44is disposed behind the stent so as to remove the stent from the device37.

A preferred method of installing the device 10 to bypass an occlusion isas follows. An small incision or puncture is made in the skin andfascial layer 46 approximately midway between the area to be bypassedand at area where the bypass will terminate. The delivery device 37containing the central member and one of the stents connected to thecentral member is inserted through the midway incision and tunneledeither proximally or distally of the blockage toward a predeterminedstent entry site. A small puncture 48 is made through the lumen orvessel wall 50 near one stent entry site. When the bypass requires adevice 10 short in length, the delivery device 37 is simply turneddownward and inserted into the puncture 48 in the lumen. If the puncture48 is made downstream of the blockage, the guide wire is used to guidethe device into the lumen with the distal stent 14 being inserted intothe lumen in a collapsed state through the downstream puncture 48.Pusher member 44 is pushed forward so as to extract the distal stent 14from the delivery device 37. The distal stent 14 then self-expands so asto engage the interior wall of the lumen. The device 37 may be slid overthe central member and moved out from either the midway incision or theincision in the skin and fascial layer near the stent entry site,leaving the stent in the lumen, with the central member coupled thereto.Instead of sliding the device 37 so as to remove it from the stent andcentral member, the device may include longitudinal slits therein. Theslits permit the device to be peeled away from the central member andthen removed. Upon removal of the device 37, the distal member 28 isdisposed so as to extend through the downstream puncture.

If a bypass of significant length is required, for example a bypass fromthe groin to an area below the knee, several small incisions may be madein the skin and fascial layer to assist in the tunnelling of the centralmember. Thus, the delivery device 37 can be inserted into the midwayincision and tunneled, then drawn out of another incision located alongthe path of tunneling, then reinserted into that incision, until thedelivery device 37 and central member are tunneled toward the incisionin the skin and fascial layer at one end of the bypass region. Thedelivery device 37 is then drawn out of the incision in the skin andfascial layer and then reinserted thereinto at an appropriate angle soas to access the lumen which may be disposed deeply within the fasciallayer. The stent 14 is then inserted into the lumen through the puncture48 as explained above, and the delivery device 37 is removed from theincision in the skin and fascial layer near the stent entry site.

The procedure is repeated at the other side of the blockage 52. Thus,the proximal stent is coupled to the other end of the central member andthe proximal stent and central member are placed into the deliverydevice 37. The delivery device 37 is then inserted into the midwayincision and tunnelled toward the other stent entry site. A secondpuncture 54 is made in the lumen at the other stent entry site. Theproximal stent 12 is inserted into the lumen via the delivery device 37in a collapsed state through the puncture 54. The proximal stent is thenejected from the delivery device and the delivery device 37 is thenpeeled away from the central member and removed, leaving the proximalmember 20 extending through the puncture 54. The delivery device is thenwithdrawn from the midway or incision in the skin and fascial layer nearthe stent entry site leaving the central member 16 disposed between theproximal and distal members. As explained above, when a bypass ofsignificant length is required, several small incisions may be made inthe skin and fascial layer to assist in the tunnelling of the centralmember. Further, the delivery device 37 may need to be removed from theincision in the skin and fascial layer near the stent entry site and bereoriented and reinserted at the appropriate angle so as to access thelumen.

Thus, as shown in FIG. 1, the proximal and distal stents are disposedwithin the lumen and the proximal, central and distal members aredisposed within the skin and fascial layer to bypass the blockage 52. Asshown by the arrows in FIG. 1, blood may flow into the proximal stent,through the central member, and out through the distal stent. Thus, alengthy and deep incision at either end of the bypass is eliminated dueto the tunnelling procedure and the percutaneous placement of thestents.

The size of the expanded stents 12, 20 and/or 14 and 28 are matched tothe size of the vessel based on an earlier performed diagnosticarteriogram or diagnostic venogram.

It can be appreciated that the order of placing of the stents depends onthe particular application. Thus, it may be preferable to place theproximal stent first within the lumen and then, thereafter, place thedistal stent within the lumen.

The device 10 can be used to bypass an arterial blockage and a venousblockage and is also applicable to create an artery to vein graft. Itcan be appreciated that the installation procedure outlined above may beemployed to graft two different lumens. Thus, instead of making twopunctures in the same lumen, one puncture is made in each of the twolumens to be connected. The proximal stent 12 is installed in one lumenand the distal stent 14 is installed in the other lumen, with thecentral member 16 providing communication between the two lumens. Thus,when functioning as an artery-vein graft, the device 10 communicatesbetween an artery and a vein rather than between separate regions of thesame artery or the same vein.

Arterial bypass grafts, venous bypass grafts, or artery-venous graftsare traditionally performed in an operating room by a surgeon skilled invascular procedures. However, the percutaneous graft or bypass device 10does not require formal surgical procedures and lengthy incisions andmay be placed non-surgically, enabling the procedure to be performedunder local anesthesia in, for example, a radiology department. Suturesare not required to couple the device to the lumen, but may be employedif desired. Since the sizes of the distal and the proximal tubularstents are preferably preselected based on lumen size, proper fit withinthe lumen is generally realized upon expansion thereof.

It is within the contemplation of the invention that the distal andproximal stents may be joined with a vein (natural material) instead ofusing the central member, composed of synthetic material. Thus, forexample, a saphenous vein can be harvested from the patient and used inplace of the central member, with the distal and proximal stents actingas the anchors for the bypass or graft. The use of a vein would bedesirable when a long bypass is required, for example, a bypass from thegroin to the calf or ankle. The use of a vein with the proximal anddistal stents would be performed in an operating room by a vascularsurgeon utilizing the above-mentioned procedure. Further, the proceduremakes the surgeon's job easier since placement difficulty and the degreeof dissection is minimized. Another advantage of using the proximal anddistal stents with the vein is that the incisions in the region to bebypassed are kept small.

It can be seen that the device of the present invention provides aneffective means of bypassing a blockage within arteries or veins and/orproviding communication between an artery and a vein. The provision ofthe proximal and distal members extending from the puncture sitesensures that a non-surgical procedure may be employed when using acentral member of prosthetic material, since sutures are not required.Further, the proximal and distal stents may be used with naturalmaterial when longer bypasses are required.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is understood that the invention is not limited to the disclosedembodiment but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. A prosthetic device comprising:a generallytubular proximal stent having a central axis and a flow passage definedtherethrough and being sized for insertion into a target lumen, saidproximal stent including a proximal member extending from a sidewallthereof so as to be in flow communication with said flow passage; agenerally tubular distal stent having a central axis and a flow passagedefined therethrough and being sized for insertion into a target lumen,said distal stent including a distal member extending from a sidewallthereof so as to be in flow communication with the flow passage of thedistal stent; and a generally tubular central member having first andsecond ends and extending between the said proximal member and saiddistal member and being in flow communication therewith so as to provideflow communication between said proximal and said distal stents, saidproximal and distal stents being constructed collapsible expandable andare and arranged so as to engage walls of the target lumen.
 2. Thedevice as defined in claim 1, wherein each of said proximal and distalmembers extend from said proximal and distal stents to define agenerally "Y" juncture.
 3. The device as defined in claim 1, whereineach of said proximal and distal stents comprise metal mesh, said firstand second ends of said central member being hooded over said proximalmember and said distal member, respectively, in such a manner to providesubstantially sealed flow communication between said proximal and saiddistal stents.
 4. The device as defined in claim 1, wherein the centralmember is composed of polytetrafluoroethylene.
 5. The device as definedin claim 3, wherein said first and second ends of the central member aresewn to said proximal and distal members respectively.
 6. The device asdefined in claim 3, wherein said first and second ends of the centralmember are attached by adhesive to said proximal and distal membersrespectively.
 7. The device as defined in claim 3, wherein the ends ofthe central member are flared.
 8. The device as defined in claim 3,wherein ends of the proximal and distal members are coated with asealing material.
 9. The device as defined in claim 1, wherein thedistal member is made integral with the distal stent and the proximalmember is made integral with the proximal stent.
 10. The device asdefined in claim 1, wherein the proximal member is disposed at anincline with respect to the central axis of the proximal stent so thatan open end thereof is directed toward the distal member and the distalmember is disposed at an incline with respect to the central axis of thedistal member so that an open end of the distal member is directedtoward the open end to the proximal member.
 11. The device as defined inclaim 1, wherein each of the proximal and distal stents are generallycylindrical and have at least one open end and wherein each of theproximal and distal members are generally cylindrical tubular membershaving open ends.
 12. The device as defined in claim 1, wherein each ofthe proximal and distal stents include retention braces adapted tocontact an inner wall of the target lumen.
 13. A prosthetic device forbypassing an occlusion in a lumen, the device comprising:a generallytubular proximal stent having a central axis and a flow passage definedtherethrough and being sized for insertion into the lumen upstream ofthe occlusion, said proximal stent including a proximal member extendingfrom a sidewall thereof so as to be in flow communication with the flowpassage; a generally tubular distal stent having a central axis and aflow passage defined therethrough and being sized for insertion into thelumen downstream of the occlusion, said distal stent including a distalmember extending from a sidewall thereof so as to be in flowcommunication with the flow passage of the distal stent; and a generallytubular central member having first and second ends and extendingbetween said proximal member and said distal member and being in flowcommunication therewith so as to provide flow communication between saidproximal and said distal stents so as to bypass the occlusion, saidproximal and distal stents being constructed collapsible and expandableand are and arranged so as to engage walls of the target lumen.
 14. Thedevice as defined in claim 13, wherein each of said proximal and distalmembers extend from said proximal and distal stents to define agenerally "Y" configuration.
 15. The device as defined in claim 14,wherein each of said proximal and distal stents comprise metal mesh,said first and second ends of said central member being hooded over saidproximal member and said distal member, respectively, in such a mannerto provide substantially sealed flow communication between said proximaland said distal stents.
 16. The device as defined in claim 13, whereinthe proximal member is disposed at an incline with respect to thecentral axis of the proximal stent so that an open end thereof isdirected toward the distal member and the distal member is disposed atan incline with respect to the central axis of the distal member so thatan open end of the distal member is directed toward the open end to theproximal member.
 17. The device as defined in claim 13, wherein each ofthe proximal and distal stents are generally cylindrical and have atleast one open end and wherein each of the proximal and distal membersare generally cylindrical tubular members having open ends.
 18. A methodof installing a device within an occluded lumen so as to bypass theocclusion, the device including a generally tubular first stent having acentral axis and a flow passage defined therethrough and being sized forinsertion into the occluded lumen, said first stent including a firstmember extending from a sidewall thereof so as to be in flowcommunication with the flow passage; a generally tubular second stenthaving a central axis and a flow passage defined therethrough and beingsized for insertion into the occluded lumen, said second stent includinga second member extending from a sidewall thereof so as to be in flowcommunication with the flow passage of the second stent; and a generallytubular central member having first and second ends coupled to saidfirst member and said second member respectively, so as to providecommunication between said first and said second stents, the methodcomprising the steps of:making a first puncture through a wall of theoccluded lumen at a position at one stent entry site one of upstream anddownstream of the occlusion; inserting the first stent in a collapsedstate through the first puncture into the occluded lumen; permitting thefirst stent to expand so as to engage the interior wall of the occludedlumen; permitting the first member to extend through the first puncture;making a second puncture through the wall of the occluded lumen at ananother stent entry site so that the occlusion is disposed between thefirst and second punctures; inserting the second stent in a collapsedstate through the second puncture into the occluded lumen; permittingthe second stent to expand so as to engage the interior wall of theoccluded lumen; permitting the second member to extend through thesecond puncture; and disposing the central member between the first andsecond members within subcutaneous tissue and fascia so that fluid mayflow through the first stent and first member, through the centralmember and second member and out through the second stent so as tobypass the occlusion.
 19. The method as defined in claim 18, wherein thecentral member of the device is composed of synthetic material.
 20. Amethod of grafting first and second lumens with a device, the deviceincluding a generally tubular first stent having a flow passage definedtherethrough and being sized for insertion into the first lumen, saidfirst stent including a first member extending from a sidewall thereofso as to be in flow communication with the flow passage; a generallytubular second stent having a flow passage defined therethrough andbeing sized for insertion into the second lumen, said second stentincluding a second member extending from a sidewall thereof so as to bein flow communication with the flow passage of the second stent; and agenerally tubular central member having first and second ends coupled tosaid first member and said second member respectively, so as to be inflow communication with said first and said second stents, the methodcomprising the steps of:making a first puncture through a wall of thefirst lumen; inserting the first stent in a collapsed state through thefirst puncture and into the first lumen; permitting the first stent toexpand so as to engage the interior wall of the first lumen; permittingthe first member to extend through the first puncture; making a secondpuncture through a wall of the second lumen at another stent entry site;inserting the second stent in a collapsed state through the secondpuncture and into the second lumen; permitting the second stent toexpand so as to engage the interior wall of the second lumen;p`permitting the second member to extend through the second puncture;and disposing the central member between the first and second memberswithin subcutaneous tissue and fascia so that fluid may flow through thefirst stent and first member, through the central member and secondmember and out through the second stent so as to permit communicationbetween said first and second lumens.
 21. A prosthetic device forcreating flow communication between first and second lumens, the devicecomprising:a generally tubular proximal stent having a central axis anda flow passage defined therethrough and being sized for insertion intothe first lumen, said proximal stent including a proximal memberextending from a sidewall thereof so as to be in flow communication withthe flow passage; a generally tubular distal stent having a central axisand a flow passage defined therethrough and being sized for insertioninto the second lumen, said distal stent including a distal extendingfrom a sidewall thereof so as to be in flow communication with the flowpassage of the distal stent; and a generally tubular central memberhaving first and second ends and extending between said proximal memberand said distal member and being in flow communication therewith so asto provide flow communication between said proximal and said distalstents and thus said first and second lumens, and said proximal anddistal stents being constructed collapsible and expandable and arearranged so as to engage walls of the target lumen.
 22. A method ofinstalling a device to bypass an occluded lumen, the device including agenerally tubular first stent having a central axis and a flow passagedefined therethrough and being sized for insertion into the occludedlumen, said first stent including a first member extending from asidewall thereof so as to be in flow communication with the flowpassage; a generally tubular second stent having a central axis and aflow passage defined therethrough and being sized for insertion into theoccluded lumen, said second stent including a second member extendingfrom a sidewall thereof so as to be in flow communication with the flowpassage of the second stent; and a generally tubular central memberhaving first and second ends and adapted to extend between said firstmember and said second member so as to provide communication betweensaid first and said second stents, the method comprising the stepsof:making an incision in skin and fascial layer generally adjacent saidocclusion; tunneling the central member in the skin and fascial layerwith the first and second stents affixed thereto so the first and secondstents are oriented in a manner such that the occlusion is disposedgenerally therebetween; making a first puncture through the occludedlumen wall at a position one of upstream and downstream of theocclusion; inserting the first stent in a collapsed state through thefirst puncture into the occluded lumen; permitting the first stent toexpand so as to engage the interior wall of the occluded lumen;permitting the first member to extend through the first puncture; makinga second puncture through the lumen wall at a position adjacent saidfirst puncture so that the occlusion is disposed between the first andsecond punctures; inserting the second stent in a collapsed statethrough the second puncture into the occluded lumen; permitting thesecond stent to expand so as to engage the interior wall of the occludedlumen; permitting the second member to extend through the secondpuncture so that fluid may flow through the first stent and firstmember, through the central member and second member and out through thesecond stent so as to bypass the occlusion.